Folded cantilever beam accelerometer

Abstract

A cantilever beam has a proof mass arranged at its distal end so as to cause the beam to resiliently deform into an S-shape when the accelerometer is subjected to acceleration intended to be detected. Strain gauge elements are placed at the two knees of the S-shape.

What is claimed is: 
     
       1. An accelerometer comprising a mount and a proof mass that are spaced apart along a longitudinal direction, said mount and said proof mass are joined by a pair of longitudinally extending, laterally spaced apart, parallel cantilever beams that are flat and straight in the absence of the application of external acceleration forces to the proof mass along a sensing axis that is transverse to the longitudinal direction, but that flex to S-shapes when such forces are applied, said proof mass extending longitudinally back toward said mount from locations where said beams join with said proof mass such that the bulk of said proof mass is spaced from said cantilever beams in the direction of said sensing axis, the center of gravity of said proof mass is disposed longitudinally between the locations where said beams join with said proof mass and where said beams join with said mount, said proof mass has a lateral extent spanning the lateral distance between said beams, and the center of gravity of said proof mass is laterally centered between said beams, including sensing means mounted on said beams for sensing flexing of said beams in response to acceleration forces along said axis. 
     
     
       2. An accelerometer as set forth in claim 1 in which said sensing means comprises multiple strain gauges disposed at respective locations on said beams where maximum curvature into S-shapes occurs.